EP4380328A1 - Field device for automation technology - Google Patents

Abstract

Field device of automation technology (10), comprising: - a field device housing (12); - a field device electronics (15) with at least a first circuit board (15.1) and a second circuit board (15.2), wherein the first and the second circuit board (15.1, 15.2) are electrically connected to one another at a first circuit board edge (15.11) of the at least first circuit board (15.1) via a first plug and mating plug connection (15.4), - wherein at least the first circuit board (15.1) has an outer contour on the second circuit board edge (15.12) such that the first circuit board has two spring arm-like segments (15.15) on the side, which are formed by corresponding shapes of the outer contour on the circuit board edges (15.13, 15.14) of the first circuit board directed towards a side wall of the field device housing, wherein the at least first circuit board (15.1) is further introduced into the field device housing (12) in such a way is that the spring arm-like segments (15.15) generate a tension along the longitudinal axis (70) of the field device housing, so that the first plug and mating plug connection (15.5) arranged on the first circuit board edge (15.11) of the at least first circuit board (15.1) are pressed into one another.

Description

The invention relates to a field device in automation technology.

Field devices that are used in industrial plants are known from the state of the art. Field devices are often used in process automation technology as well as in production automation technology. In principle, field devices are all devices that are used close to the process and provide or process process-relevant information. Field devices are used to record and/or influence process variables. Measuring devices or sensors are used to record process variables. These are used, for example, for pressure and temperature measurement, conductivity measurement, flow measurement, etc. and record the corresponding process variables pressure, temperature, conductivity, pH value, fill level, flow rate, etc. Actuators are used to influence process variables. These are, for example, pumps or valves that can influence the flow of a liquid in a pipe or the fill level in a container. In addition to the measuring devices and actuators mentioned above, field devices also include remote I/Os, radio adapters or general devices that are arranged at the field level.

A large number of such field devices are produced and distributed by the Endress+Hauser Group.

Such field devices have a sensor element, in particular at least partially and/or at least partially in contact with a process medium, which serves to generate a signal dependent on the process variable. Furthermore, these field devices have an electronic unit arranged in a housing, wherein the electronic unit serves to process and/or forward signals generated by the sensor unit, in particular electrical and/or electronic signals. Typically, the electronic unit comprises several circuit boards with components arranged thereon. The circuit boards are usually arranged in a circuit board holder and mechanically fixed.

The disadvantage of such a structure, consisting of several circuit boards, is that the necessary electrical connections, which are usually made using plug and mating plug connections, do not function permanently or reliably. The reason for this is that tolerances can lead to play in the plug and mating plug connections, so that in the worst case the plug and mating plug connections become separated.

The invention is therefore based on the object of proposing a field device for automation technology in which the circuit boards are reliably electrically contacted via a plug and mating plug connection.

The object is achieved according to the invention by the field device of automation technology according to patent claim 1.

• ein Feldgerätegehäuse;
• eine in dem Feldgerätegehäuse angeordnete Feldgeräteelektronik mit zumindest einer ersten Leiterplatte, die vorzugsweise entlang einer Längsachse des Feldgerätegehäuse ausgerichtet bzw. orientiert ist und einer zweiten Leiterplatten, die vorzugsweise quer zu einer Längsachse des Feldgerätegehäuses ausgerichtet bzw. orientiert ist, wobei die erste und die zweite Leiterplatte an einer ersten Leiterplattenkante der zumindest ersten Leiterplatte über eine erste Steck- und Gegensteckverbindung elektrisch miteinander verbunden sind,
• wobei zumindest die erste Leiterplatte an der der ersten Leiterplattenkante gegenüberliegenden zweiten Leiterplattenkante eine derartige Außenkontur aufweist, dass die erste Leiterplatte seitlich zwei federarmähnliche Segmente aufweist, die durch entsprechende Ausformungen der Außenkontur an den zu einer Seitenwandung des Feldgerätegehäuses gerichteten Leiterplattenkanten der ersten Leiterplatte ausgebildet sind, wobei die zumindest erste Leiterplatte ferner derartig in das Feldgerätegehäuse eingebracht ist, dass die federarmähnlichen Segmente eine Spannung entlang der Längsachse des Feldgerätegehäuses erzeugen, so dass die an der ersten Leiterplattenkante der zumindest ersten Leiterplatte angeordnete erste Steck- und Gegensteckverbindung ineinander gepresst wird.

The field device of automation technology according to the invention comprises:

• a field device housing;
• a field device electronics arranged in the field device housing with at least a first circuit board, which is preferably aligned or oriented along a longitudinal axis of the field device housing and a second circuit board, which is preferably aligned or oriented transversely to a longitudinal axis of the field device housing, wherein the first and the second circuit board are electrically connected to one another at a first circuit board edge of the at least first circuit board via a first plug and mating plug connection,
• wherein at least the first circuit board has an outer contour on the second circuit board edge opposite the first circuit board edge such that the first circuit board laterally has two spring arm-like segments which are formed by corresponding formations of the outer contour on the circuit board edges of the first circuit board directed towards a side wall of the field device housing, wherein the at least first circuit board is further introduced into the field device housing such that the spring arm-like segments generate a tension along the longitudinal axis of the field device housing, so that the first plug and mating plug connection arranged on the first circuit board edge of the at least first circuit board are pressed into one another.

An advantageous embodiment of the field device according to the invention in automation technology can provide that the field device electronics arranged in the field device housing further comprises a further circuit board, which is preferably aligned or oriented transversely to the longitudinal axis of the field device housing, wherein the further and the first circuit board are electrically connected to one another at the second circuit board edge of the first circuit board via a second plug and mating plug connection, wherein the further circuit board is mechanically fixed in the field device housing and wherein the further circuit board has corresponding abutments for the spring arm-like segments of the first circuit board, wherein the abutment and the first and the further circuit board are arranged and/or designed in such a way that when the second plug and mating plug connection is plugged in, the spring arm-like segments of the first circuit board are held together by the Abutments of the further circuit board are supported in such a way that the tension is generated along the longitudinal axis of the field device housing and thus the first plug and counter plug connection arranged on the first circuit board edge of the at least first circuit board is pressed into one another. In particular, the design of the field device according to the invention for automation technology can provide that the spring arm-like segments on the second circuit board edge of the first circuit board each have at least one protruding stop surface for support on the abutments of the further circuit board and/or parts of an underside of the further circuit board serve as abutments.

A further advantageous embodiment of the field device according to the invention in automation technology can provide that the field device further comprises a circuit board holder arranged in the field device housing for holding at least the further circuit board, wherein the further circuit board is mechanically fixed in the field device housing by the circuit board holder, wherein the circuit board holder is adapted with a circumferential outer contour of a wall at least in a partial section to an inner contour of the field device housing such that the outer contour of the circuit board holder lies essentially flush with the inner contour of the field device housing, wherein the circuit board holder in the region of the partial section has at least one latching mechanism for fastening the first circuit board and the first circuit board, in particular the spring arm-like segments of the first circuit board, at least one corresponding to the latching mechanism of the circuit board holder

Have a counter-latching mechanism, wherein the latching and counter-latching mechanism are coordinated and designed in such a way that in the latched state, slipping, in particular slipping out, of the first circuit board from the circuit board holder is prevented but an axial movement of the first circuit board is nevertheless possible in the latched state, so that the first plug and counter plug connection are pressed into one another by the tension generated along the longitudinal axis of the field device housing.

A further advantageous embodiment of the field device according to the invention for automation technology can provide that the field device further comprises a circuit board holder arranged in the field device housing for holding at least the first and/or the second circuit board, wherein the circuit board holder is adapted with a circumferential outer contour of a wall at least in a partial section to an inner contour of the field device housing in such a way that the outer contour of the circuit board holder lies essentially flush with the inner contour of the field device housing, wherein the circuit board holder comprises corresponding abutments for the spring arm-like segments of the first circuit board, which are arranged and designed in such a way that the spring arm-like segments of the first circuit board in an introduced State in which the first circuit board is inserted into the circuit board holder, supported by the abutments in such a way that the tension is generated along the longitudinal axis of the field device housing and thus the first plug and counter plug connection arranged on the first circuit board edge of the at least first circuit board are pressed into one another. In particular, the design can provide that the abutments are designed in the form of recesses, in particular openings, which are made in the wall of the circuit board holder.

A further advantageous embodiment of the field device according to the invention in automation technology can provide that the circuit board holder has a cup-like shape.

A further advantageous embodiment of the field device according to the invention in automation technology can provide that the spring arm-like segments each have an elongated web, which preferably has a length in the range of 5 - 20 mm and/or preferably a width in the range of 1.5 - 0.5 mm, preferably in the range of 0.8 - 1.2 mm.

• Fig. 1: eine Schnittdarstellung durch ein erfindungsgemäßes Feldgerät der Automatisierungstechnik,
• Fig. 2: eine Schnittdarstellung durch den Innenraum des Feldgerätegehäuses, und
• Fig. 3: eine erfindungsgemäß ausgebildete Leiterplatte für eine sich in dem Innenraum befindliche Feldgeräteelektronik.

The invention is explained in more detail with reference to the following drawings. It shows:

• Fig.1 : a sectional view through an inventive field device for automation technology,
• Fig.2 : a sectional view through the interior of the field device housing, and
• Fig.3 : a circuit board designed according to the invention for field device electronics located in the interior.

Fig.1 shows an example of a sectional view of a field device in automation technology. The field device 10 comprises a field device housing 12 which encloses an interior space 13. The field device housing 12 has an area 17 which is rotationally symmetrical at least in sections and into which a circuit board holder 16, which will be described in more detail later, can be inserted.

Furthermore, the field device 10 comprises a sensor assembly arranged at the end of the field device housing 12 with a sensor and/or actuator element 14 for setting and/or detecting a process variable and a process connection 28. The process connection 28 can be a threaded design or a screwable or clampable flange.

In the present exemplary embodiment, the sensor and/or actuator element 14 comprises a fill level sensor element for detecting a fill level as a process variable. Nevertheless, the invention is not limited to the type or specific design of the sensor and/or actuator element as a fill level sensor element, but can in principle be transferred to any other sensor or actuator principle.

Field device electronics 15, which are installed in an interior space 13 of the field device housing and are designed to operate the sensor and/or actuator element 14, are used to provide and/or process a sensor and/or actuator signal.

In the present exemplary embodiment, the field device electronics have a first circuit board 15.1 and a third circuit board 15.3, which are each aligned along a longitudinal axis of the field device housing 70 in the interior, and a second circuit board 15.2, which is aligned or oriented transversely to the longitudinal axis of the field device housing, so that the first and third circuit boards 15.1, 15.3 are aligned at an angle of 90° to the second circuit board 15.2 or are orthogonal to one another. The first and second circuit boards 15.1, 15.2 are electrically connected to one another via a first, preferably rigid plug and mating plug connection 15.5. For this purpose, the first circuit board 15.1 can have a preferably rigid plug connector on its first circuit board edge 15.11 and the second circuit board 15.2 can have a corresponding, preferably also rigid mating plug connector, which are designed and coordinated with one another in such a way that they can be plugged into one another.

The field device electronics 15 further comprises a fourth circuit board 15.4 serving as connection electronics 20, which is aligned transversely to the longitudinal axis 70 of the field device housing and is thus oriented essentially parallel to the second circuit board 15.2. In the exemplary embodiment shown, the field device electronics are designed such that the second circuit board 15.2 arranged transversely to the longitudinal axis and the fourth circuit board 15.4 also arranged transversely to the longitudinal axis limit or enclose the two other circuit boards 15.1 and 15.3, which are arranged along the longitudinal axis, at the top and bottom. The fourth circuit board 15.4 serving as connection electronics 20 comprises a field contact plug 21, which is arranged in a longitudinal axis of the circuit board 25 on a circuit board edge and is soldered to it. The field contact plug 21 can be used to transmit data, in particular measured values, from the field device 10 to an external unit, for example a higher-level unit or another field device.

In addition or as an alternative, the power supply for the field device can also be implemented via the field contact plug. The field contact plug 21 can in particular be a circular connector, e.g. an M12 circular connector In order to lead the field contact plug to the outside, the field device housing 12 has a correspondingly designed housing opening 18. The fourth circuit board 25 can also be electrically connected to the first circuit board 15.1 via a second plug and mating plug connection 15.6. Furthermore, electronic components for EMC and/or explosion protection measures 24 can be applied to the fourth circuit board 15.4.

At an upper end of the field device 10, the field device housing 12 has a display for display and/or operation 19. The display 19 can have capacitive buttons for operation. These can be implemented, for example, using a corresponding capacitive film. In order to meet the hygienic requirements, the display can be arranged behind a viewing or operating panel 11 integrated in the housing 12 in the interior 13 of the field device. In order to have the best possible representation or readability of the information on the display 19 placed behind the viewing panel 11 and/or to have friction-free operation of capacitive buttons, the display 19 should lie as flat and/or evenly as possible on the back of the viewing or operating panel 11. For example, a display frame 30 can be used for this, which on the one hand accommodates the display and on the other hand places it accordingly behind the viewing or operating panel 11.

The circuit boards 15.1 to 15.4 of the field device electronics 15 can be arranged at least partially in a circuit board holder 16 so that they can be mechanically fixed by this. The circuit board holder 16 is designed with its outer contour in such a way that it lies essentially flush against an inner wall of the rotationally symmetrical area, at least in sections.

In the embodiment shown, the circuit board holder 16 has a cup-like shape. To accommodate the circuit boards, the circuit board holder 16 can have lateral guide rails on an inner side through which the circuit boards oriented/arranged along the longitudinal axis of the field device housing are guided. In this case, two guide rails, preferably arranged diametrically to one another, can be provided for accommodating a circuit board. The circuit board holder is used in the Fig.1 In the embodiment shown, the fourth circuit board 15.4 serving as connection electronics is mechanically fixed.

According to the invention, the first circuit board 15.1 is designed in such a way that it has an outer contour on the second circuit board edge 15.12 opposite the first circuit board edge 15.11 such that the first circuit board 15.1 has two spring-arm-like segments 15.15 on the side. The spring-arm-like segments 15.15 can be produced, for example, by appropriate milling of the outer contour of the circuit board. become. Fig.2 shows such a circuit board 15.1 inserted into the circuit board holder 16 with correspondingly designed spring arm-like segments 15.15 and Fig.3 the free circuit board 15.1. The spring arm-like segments are designed in such a way that they each have an elongated web 15.153. The elongated web 15.153 can be designed in such a way that it has a width B in the range of 1.5 - 0.5 mm, preferably in the range of 0.8 - 1.2 mm with a circuit board thickness of approx. 1 mm. Furthermore, the elongated web can have a length in the range of 5 - 20 mm.

In addition, as can be seen from Fig.3 As can be seen, the spring arm-like segments 15.15 on the second circuit board edge 15.12 of the first circuit board 15.1 each have at least one protruding stop surface 15.151 for support on abutments 15.41 of the fourth circuit board 15.4. For example, a rear side of the fourth circuit board 15.4 mechanically fixed in the field device housing 12 can serve as the abutment 15.41. The fourth circuit board 15.4 is advantageously mechanically fixed in the field device housing 12 by the circuit board holder 16. Alternatively, it can also be mechanically fixed in the field device housing 12 in another way without the circuit board holder.

In addition, the circuit board holder 16 can comprise a latching mechanism 60a for the robust fastening of the first circuit board 15.1. The first circuit board 15a itself in turn comprises a corresponding counter-latching mechanism 60b for this purpose. The spring arm-like segments 15.15 are preferably designed in such a way that they have the counter-latching mechanism 60b. This can be achieved, for example, by latching lugs 15.152 attached to the sides of the spring arm-like segments 15.15. The latching or counter-latching mechanism 60a, 60b is arranged in the upper area of the circuit board holder, i.e. on the side of the circuit board holder 16 facing away from the sensor and/or actuator element 14. By means of a suitably designed latching and counter-latching mechanism 60a, 60b, it is possible during the manufacture of the field device electronics to prevent the first circuit board from slipping, in particular from slipping out, from the circuit board holder 16 in the situation where the fourth circuit board 15.4 has not yet been introduced into the interior 13 of the field device housing 12. The latching and counter-latching mechanism 60a, 60b is also designed such that, despite the latching into one another, an axial movement of the first circuit board is possible, so that the first plug and counter plug connection 15.5 are pressed into one another by the generated tension along the longitudinal axis 70 of the field device housing.

As an alternative to the support on the abutments of the fourth circuit board 15.4, the circuit board holder 16 can also have correspondingly designed abutments through which the spring arm-like segments 15.15 of the fourth circuit board 15.4. In particular, the abutments can be designed in the form of recesses, preferably in the form of openings, which are made in the wall of the circuit board holder.

Due to the spring arm-like segments 15.15 of the first circuit board 15.1, it is thus possible for the first circuit board 15.1 to generate a tension along the longitudinal axis 70 of the field device housing 12 when it is inserted into the field device housing 12 or in the installed state, so that the first plug and mating plug connection 15.5 arranged on the first circuit board edge 15.11 are pressed into one another in order to be able to compensate for production-related tolerances, for example.

Furthermore, the circuit board holder 16 can be cast using casting compound 27 up to a predetermined casting height 27a. Silgel, for example, can serve as the casting compound. The casting height 27a is usually set such that the casting compound takes up approximately half to two-thirds of the volume of the circuit board holder 16. If necessary, the casting compound can also take up significantly more than half or two-thirds of the volume of the circuit board holder 16. The locking and counter-locking mechanism 60a, 60b is then arranged in the area of the circuit board holder 16 or the circuit board 15a that is not cast. In combination with the casting compound, the locking and counter-locking mechanism prevents the circuit board from floating in the casting cup as long as the casting compound has not yet hardened.

List of reference symbols

10

Field device in automation technology

11

Viewing window

12

Field device housing

13

inner space

14

Sensor and/or actuator element

15

Field device electronics

15.1

First circuit board

15.11

First PCB edge of the first PCB

15.12

Second PCB edge of the first PCB

15.13

Third or side PCB edge of the first PCB

15.14

Fourth or side PCB edge of the first PCB

15.15

Spring arm-like segments

15,151

Protruding stop surfaces

15,152

locking lug

15,153

Elongated bridge

15.2

Second circuit board

15.3

Third circuit board

15.4

Additional circuit board serving as connection electronics

15.41

Abutment of the other circuit board

15.5

First plug and mating connector

15.6

Second plug and mating plug connection

15.7

Third plug and mating connector

16

PCB holder

17

Rotationally symmetrical sub-area

18

Housing opening

19

Display

20

Connection electronics

21

Field contact plug

24

Electronic components, e.g. for EMC and/or explosion protection measures

26

Plug sleeve for field contact plug

27

Casting compound

27a

Predetermined potting height up to which the circuit board in the circuit board holder is potted with the potting compound

28

Process connection

30

Display frame

40

Display holder

50

Carrier plate or circuit board

B

Detailed view of the locking and counter-locking mechanism

60a

Snap-in mechanism of the circuit board holder, especially recess

60b

Counter-locking mechanism of the first circuit board

70

Longitudinal axis of the field device

B

Width of the spring arm-like segment

L

Length of the spring arm-like segment

Claims (8)

Field device of automation technology (10), comprising: - a field device housing (12); - a field device electronics (15) arranged in the field device housing with at least a first circuit board (15.1), which is preferably aligned or oriented along a longitudinal axis (70) of the field device housing (12), and a second circuit board (15.2), which is preferably aligned or oriented transversely to a longitudinal axis (70) of the field device housing (12), wherein the first and the second circuit board (15.1, 15.2) are electrically connected to one another at a first circuit board edge (15.11) of the at least first circuit board (15.1) via a first plug and mating plug connection (15.5), - wherein at least the first circuit board (15.1) has an outer contour on the second circuit board edge (15.12) opposite the first circuit board edge (15.11) such that the first circuit board has two spring arm-like segments (15.15) on the side, which are formed by corresponding formations of the outer contour on the circuit board edges (15.13, 15.14) of the first circuit board directed towards a side wall of the field device housing (12), wherein the at least first circuit board (15.1) is further introduced into the field device housing (12) such that the spring arm-like segments (15.15) generate a tension along the longitudinal axis (70) of the field device housing (12), so that the first plug and mating plug connection (15.5) arranged on the first circuit board edge (15.11) of the at least first circuit board (15.1) are pressed into one another. Field device of automation technology according to claim 1, wherein the field device electronics (15) arranged in the field device housing (12) further comprises a further circuit board (15.4), which is preferably aligned or oriented transversely to the longitudinal axis (70) of the field device housing (12), wherein the further and the first circuit board (15.1, 15.4) are electrically connected to one another at the second circuit board edge (15.12) of the first circuit board (15.1) via a second plug and counter plug connection (15.6), wherein the further circuit board (15.4) is mechanically fixed in the field device housing (12) and wherein the further circuit board (15.4) has corresponding abutments (15.41) for the spring arm-like segments (15.15) of the first circuit board, wherein the abutment (15.41) and the first and the further circuit boards (15.1, 15.4) are arranged and/or designed in relation to one another in such a way that in In the inserted state of the second plug and mating plug connection (15.6), the spring-arm-like segments (15.15) of the first circuit board (15.1) are supported by the abutments (15.41) of the further circuit board (15.4) in such a way that the tension is generated along the longitudinal axis (70) of the field device housing (12) and thus the the first plug and mating plug connection (15.5) arranged on the first circuit board edge (15.11) of the at least first circuit board (15.1) are pressed into one another. Field device of automation technology according to the preceding claim, wherein the spring arm-like segments (15.15) on the second circuit board edge (15.12) of the first circuit board (15.1) each have at least one protruding stop surface (15.151) for supporting on the abutments (15.41) of the further circuit board (15.4) and/or parts of an underside of the further circuit board (15.4) serve as abutments (15.41). Field device of automation technology according to one of the preceding claims, further comprising a circuit board holder (16) arranged in the field device housing (12) for holding at least the further circuit board (15.4), wherein the further circuit board (15.4) is mechanically fixed in the field device housing (12) by the circuit board holder (16), wherein the circuit board holder (16) is adapted with a circumferential outer contour of a wall at least in a partial section (17) to an inner contour of the field device housing (12) in such a way that the outer contour of the circuit board holder (16) lies essentially flush with the inner contour of the field device housing (12), wherein the circuit board holder (16) in the region of the partial section (17) has at least one latching mechanism (60a) for fastening the first circuit board (15.1) and the first circuit board (15.1), in particular the spring arm-like segments of the first circuit board (15.1), at least one to the latching mechanism of the circuit board holder (60a) corresponding counter-latching mechanism (60b), wherein the latching and counter-latching mechanism (60a, 60b) are coordinated and designed such that in the latched state, slipping, in particular slipping out, of the first circuit board (15.1) from the circuit board holder (16) is prevented but nevertheless in the latched state, an axial movement of the first circuit board (15.1) is possible, so that, by the tension generated along the longitudinal axis (70) of the field device housing, the first plug and counter plug connection (15.5) are pressed into one another. Field device of automation technology according to claim 1, further comprising a circuit board holder (16) arranged in the field device housing (12) for holding at least the first and/or the second circuit board (15.1, 15.2), wherein the circuit board holder (16) is adapted with a circumferential outer contour of a wall at least in a partial section (17) to an inner contour of the field device housing (12) in such a way that the outer contour of the circuit board holder (16) lies essentially flush with the inner contour of the field device housing (12), wherein the circuit board holder (16) for the spring arm-like segments (15.15) of the first circuit board (15.1) comprises corresponding abutments, which are arranged and designed in such a way that the spring arm-like segments (15.15) of the first circuit board (15.1) in an inserted state in which the first circuit board (15.1) is inserted into the circuit board holder (16) are supported by the abutments in such a way that the tension is generated along the longitudinal axis of the field device housing (12) and thus the first plug and mating plug connection (15.5) arranged on the first circuit board edge (15.11) of the at least first circuit board (15.1) are pressed into one another. Field device of automation technology according to the preceding claim, wherein the abutments are designed in the form of recesses, in particular openings, which are made in the wall of the circuit board holder (16). Field device according to one or more of the preceding claims, wherein the circuit board holder (16) has a cup-like shape. Field device according to one or more of the preceding claims, wherein the spring arm-like segments (15.15) each have an elongated web, which preferably has a length in the range of 5 - 20 mm and/or preferably a width in the range of 1.5 - 0.5 mm, preferably in the range of 0.8 - 1.2 mm.

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